Condenser



y 1936- u. A. TADDIKEN 2,040,963

CONDENSER Filed Sept. 13, 1935 fi z ik WITNESSES: INVENTOR 2am? ULRICH H. Flam/raw.

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ATTORN EY Patented May 19, 1936 UNITED STATES PATENT OFFICE CONDENSER Pennsylvania Application September 13, 1935, Serial No. 40,354

8 Claims.

My invention relates to loop seals for conducting condensate from a region of higher absolute pressure to one of lower absolute pressure and it has for an object to provide means rendering such a seal more stable.

In power plants, it is common practice to provide a conduit for draining condensate from an inter-condenser'or cooler between ejector stages of air and non-condensable gas evacuating apparatus to the main condenser served by such evacuating apparatus; however, as the inter-condenser pressure and temperature are higher than the condenser pressure and temperature, it is necessary to provide a loop seal in the drainage conduit. In plants operating under substantially uniform conditions, no particular trouble has been experienced with seals of this character, but, where conditions of operation are variable, for example, in marine practice, some difficulty has been encountered on account of instability of such a seal, the effect of breaking down of a seal being to impair the vacuum of the condenser as well as to interfere with normal operation of the evacuating apparatus. Since the inter-condenser temperature and absolute pressure are higher than the condenser temperature and absolute pressure, the water passing to the condenser through the drainage conduit and the seal is at a higher temperature than that corresponding to the condenser vacuum or absolute pressure with the result that boiling may occur in the condenser leg of the seal. Boiling lowers the density of the column of liquid in the condenser leg due to the inclusion of steam bubbles; and, this action being 35 progressive, the level in the inter-cooler leg is lowered until the bottom of the loop is reached whereupon the seal is broken. Furthermore, momentary failure of the second stage ejector of the evacuating apparatus may result in breaking the seal, for, if such failure occurs, both the pressure and the temperature in the inter-condenser rise-and the boiling action referred to is increased. The problem overcome by the present invention isthat of minimizing the efiect of boiling sofar as rendering'the seal' unstable is concerned; According-ljg'instead of having the second, or condenser, leg of the loop seal discharging directly to the condenser, as heretofore, rprovide a storage chamber into which the second leg discharges, the storage chamber being connected to the condenser and having a conduit through which liquid may be supplied to the first, or inter-condenser, leg of the loop seal, the purpose of this arrangement being to secure cooling action of the water passing throughthe drainage conduit and before it passes through the bottom portion of the loop. Also, I prefer, to arrange the storage chamber or receptacle in heat-exchange relation with respect to the second leg of the seal, whereby water discharging from the second leg and which has been progressively cooled due to evaporation is brought into heat-exchange relation with respect to a substantial portion of the second leg, the water rising in the second leg being progressively cooled and the water moving downwardly through the storage chamber or receptacle absorbing some heat, but the temperature of water supplied from the storage chamber or receptacle to the intercooler leg is at a sufiiciently low value to efiect substantial lowering of temperature of water passing through the drainage conduit. Thus, it will be seenthat I effect lowering of the temperature of water passing through the. drainage conduit intwo ways: (1) Water from the storage chamber or receptacle is mixed with the water passing through the drainage conduit so as to produce a mixture having a lower temperature; and, (2) The mixture at lower temperature has its temperature still further reduced by the water flowing downward through the storage receptacle or chamber and in heat-exchange relation with respect to the second leg. These two effects make possible a temperature condition of water leaving the second leg which'is sufiiciently low that boiling action in the second leg is very much reduced and the seal thereby made much more stable. A further object of my invention is to provide apparatus of this character serving to secure a more efi'ective and stable seal in drains for conducting condensate from a region of'higher temperature and absolute pressure to a region of lower temperature and absolute pressure.

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawing, forming a part of this application, in which:

The figure is a diagrammatic view of power plant apparatus having my improved loop seal.-

Referring to the drawing more in detail, I show a condenser Ill provided with a hotwell ll, condensate removal apparatus I2 including a condensate outlet conduit I3, and evacuating apparatus, at M, for the removal of air and noncondensable gases from the condenser.

Ordinarily, the evacuating apparatus is comprised by two or more ejectors arranged in series, inter-condensers being employed between-adjacent ejectors and an after-condenser preferably being employed in connection with the last stage ejector. In the drawing, I show evacuating apparatus, at I4, employing a first stage ejector I5, which entrains air and non-condensable gases from the condenser and discharges such air and non-condensable gases with steam into the inter- V condenser l5, non-condensable media being withdrawn from the latter by means of a second stage ejector II which discharges into the after-condenser |8. r

f Condensate from the inter-condenser I6 is con-1 ducted by a drainage conduit I!) to the condenser,

caused to flow from the inter cooler to the condenser without any disturbance of the pressure conditions either in the inter-cooler or in the condenser.

With apparatus of this character, obviously water draining from the inter-cooler is at a higher temperature than the temperature corre- 'sponding to the vacuum existing in' the condenser,

with the result'that more or less boiling may ocour in the condenser leg of the loop seal; and in some cases, particularly where the plant is oper ated under variable conditions, boiling'has produced such lower density of water in the condenser leg that the level in the inter-cooler. leg

has been lowered to such a point that the seal is broken. 'Also,-breakage of the seal may be effected by momentary failures of the second stage.

ejector, whereby both the absolute pressure and the temperature of the'inter-cooler are raised and the tendency to boiling increased. T

To reduce the temperature of water passing through'the second or condenser leg 2|, I make Uuseof condensate issuing from the latter leg; and

which has been cooled due to boiling'or evaporation, for the purpose of'reducing temperature of condensate, by mixture therewith, before passing through the bottom, or sealing, portion 22. To this end, I provide 'a chamber 'or receptacle 23 having its upper end communicating with the condenser by means of a conduit or passage 24 and having its lower end connected by means of a conduit'25 to the inter-cooler leg 2|), at a suitable point. With this arrangement ofappara tus, it will be apparent that the boiling action in the leg 2| will produce cooling of water issuing from the latter and such cooled water enters the chamber 23 and passes from the latter both to the condenser and to the inter-cooler leg to the extent required. The collection chamber or. reservoir 2 3 provides for adequate storage of water such that any tendency to breakageof the seal is effectively resisted both because of the stored water which is potentially effective for thatpurpose and because'of the reduced temperature of =the'water, the water of reduced temperature mixing with the drainage, thereby producing a reduced temperature of the drainage and, on that account, lessening the boiling action.

In order to provide a more effective "cooling arrangement and at the same time reduce the space required for the storage receptacle 23, the

latter is preferably made as a tube of suitable length and diameter and within which the condenser leg 2| of the'loop seal is located, the leg 2| beingarrangedto discharge into the upper end portion of the tube, and the lower end portion thereof being connected by the conduit '25 to the inter-cooler'leg 20. With this arrangement, water issuing from the upper end of the leg 2|, and which has been cooled by theevapora tion action, fills the tube 23 and flows down therearound and through the conduit 25 to the extent required, the water passing downthrough the tube 23 absorbing heat from water passing upwardly through the leg 2|, whereby the temperature of drainage is progressively reduced; and, while this action'resultsin a rise in temperature V of the water passing downwardly through thetube 23, nevertheless the Water issuing therefrom andt hrough the conduit '25 is still at a sufficiently low temperature to promote effective cooling of drainage passing through the inter-cooler leg 20, the net effect of the two steps of cooling being to provide for liquid passing upwardly through the leg 2| and. issuing from the upper end'thereof with'a'minimum of boiling,

Wherebystability of the seal is maintained.

The tube 23 associated with the condenser side -2| of the loop, therefore, serves to secure recirculation of water in order-to reduce flashing action and, therefore, to reduce the tendency tobreak ing of the seal. In other words, this arrangement serves to keep the loop seal filled with liquid.

Furthermore, the storage provided by the receptacle or tube 23 affords an adequate supply of :water to re-establishthe loop seal, should the latter be broken due to momentary failure of the second stage ejector for any reason. A conduit useful in an emergency.

From the foregoing, it will beapparent that I V have devised means rendering more stable a' loop seal provided, in a drainage conduit connecting a region of higher absolute pressure andtemperature to a regionof lower pressure and absolute temperature, this purpose being effected by mak-' ing use of boiling or evaporation of water passing through the seal and which cools the remaining or unevaporated water to minimize interruption or breakage of'the seal, the water so cooledbeing recirculated in the seal in 'order to reduce the temperature of 'water passing, therethrough and through the outlet leg. thereof so as to minimize the temperature of water in the outlet leg and the consequent boiling action thereof, with the result that the seal is made more stable.

While I have shown'my invention in but one form, it will be obvious to those skilled in the art.

that it is notso limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims What I claim is:

1. In condensing apparatus, first and second.

condensing elements normally operated so that the absolute pressure and temperature in the first element are higher than in the second element, a conduit for draining condensate from the first element to the second element and including a, loop Seal having-inlet and outlet legs, a storage receptacle in communication with the second element and arranged so that the upper end of the outlet leg of the seal discharges thereinto, and a conduit for conducting liquid from the storage chamber and communicating with the inlet leg so as to secure admixture of liquid from the storage chamber with that passing through the inlet leg, whereby recirculation of liquid occurs in the loop seal in such manner as to reduce the temperature of liquid flowing through the outlet leg and consequently to reduce the boiling or flashing action.

2. In condensing apparatus, first and second condensing elements normally operated so that the absolute pressure and temperature in the first element are higher than in the second element; and means for draining condensate from the first element to the second element, said means including a loop seal having inlet and outlet legs, a tubular member of substantially larger diameter than the outlet leg and telescopically arranged with respect to the latter so that the upper end of the outlet leg is arranged to discharge in the upper portion of the tubular member, means providing for communication of the interior of the tubular member with the second element, and a conduit for supplying liquid from the lower portion of the tubular member to the inlet leg of the seal.

3. In power plant apparatus, a steam condenser; multiple-stage evacuating apparatus for removing air and non-condensable gases and including an inter-condenser between stages; and means for draining condensate from the intercondenser to the condenser, said means including a loop seal having inlet and outlet legs, a storage receptacle into which the outlet leg discharges, means aiTo-rding communication between the storage receptacle and the condenser, and means providing for liquid flowing from the storage receptacle into the inlet leg of the seal.

4. In power plant apparatus, a steam condenser; multiple-stage evacuating apparatus for removing air and non-condensable gases from the condenser and including an inter-condenser arranged between stages; and means for conducting condensate from the inter-condenser to the condenser, said means including a loop seal having inlet and outlet legs, and means providing for recirculation through the seal of water issuing from the outlet leg.

5. In power plant apparatus, a steam condenser; multiple-stage evacuating apparatus for removing air and non-condensable gases from the condenser and including an inter-condenser between stages; and means for conducting condensate from the inter-condenser to the condenser, said means including a loop seal having inlet and outlet legs, a receptacle within which the outlet leg discharges, means providing for communication of the receptacle with the condenser, and a conduit connected to the receptacle at a pointlower than the connection of said condenser communication means therewith, and said conduit being connected to the inlet leg so that water may be supplied from the receptacle to the inlet leg for admixture with condensate passing therethrough.

6. In power plant apparatus, a steam condenser; multiple stage evacuating apparatus for removing air and. non-condensable gases from the condenser and including an inter-condenser arranged between stages; means for conducting condensate from the inter-condenser to the condenser, said means including a loop seal having inlet and outlet legs, a tubular member of larger diameter than the outlet leg and telescopically arranged with respect to the latter so as to provide a. tubular receptacle into the upper end of which the outlet leg discharges, a conduit affording communication between the upper portion of the tubular receptacle and the condenser, and a conduit for supplying water from the lower portion of the tubular receptacle to the inlet leg of the seal.

'7. In power plant apparatus, a steam condenser; multiple-stage evacuating apparatus for removing air and non-condensable gases from the condenser and including an inter-condenser arranged between stages; and means for conducting condensate from the inter-condenser to the condenser, said means including a loop seal having inlet and outlet legs, a receptacle within which the outlet leg discharges, means providing for communication of the receptacle with the condenser, a conduit for supplying water from the receptacle to the inlet leg, and means providing for replenishment of the receptacle with water from an external source.

8. In power plant apparatus, a steam condenser including condensate removal means; multiplestage evacuating apparatus. for removing air and non-condensable gases from the condenser and including an inter-condenser; means for conducting condensate from the inter-condenser to the condenser, said means including a loop seal having inlet and outlet legs, a tubular member telescopically arranged with respect to the outlet leg and defining a storage receptacle into the upper end of which the outlet leg discharges, and a conduit providing for communication of the upper portion of the tubular receptacle with the condenser, a conduit for afior'ding communication between the lower portion of the tubular receptacle and the inlet leg, whereby recirculation of condensate through the seal may be eifected; a conduit for supplying condensate from the condensate removal means to the tubular receptacle in order to replenish the Water supply of the latter; and a valve in the last-named conduit for opening and closing the latter.

7 ULRICH A. TADDIKEN. 

